Rofin-Baasel UK recently supplied a manual laser welding system, the StarWeld Performance (Fig.2) to the MedicAlert Foundation. MedicAlert a registered charity (celebrating their 40th anniversary this year), is the only non-profit making registered charity providing life-saving identification jewellery for individuals with hidden medical conditions and allergies. MedicAlert jewellery ‘Emblems' are engraved with the owner's medical condition or allergy, a unique ID number and 24 hour emergency phone number.
Specifically, MedicAlert was looking to weld silver jump rings to attach their emblem bracelets ( Fig.1 ) and necklets and needed a timesaving alternative to traditional silver soldering. After experimenting with the laser welder from Rofin-Baasel they found they could achieve a better result, with higher throughput and requiring less finishing.
Silver is a difficult material to weld by laser because the high reflectivity and thermal conductivity mean that higher than normal pulse energies are required. Over the past months the MedicAlert production team has been honing the technique of welding silver jump rings and has reduced the time per jump ring from five minutes to a matter of seconds. The ring is now welded with a single high energy pulse giving an excellent finish. MedicAlert are the only organization in the UK using the laser in this way.
Alex Dayton, Head of Laser Welding Technologies at the MedicAlert Foundation who developed the new technique said:
‘The development of the One Shot Programme using the Rofin Starweld Performance Laser has made the welding of jump rings on our Silver Bracelets effortless. With one laser pulse we can create a fusion weld right through the jump ring giving us a weld far superior and quicker than traditional methods.
Productivity has greatly increased as a result of these techniques. Rofin laser spot welders are highly versatile and pulse shaping has been one of the major contributing factors to the success of the One Shot Programme.'
Key factors in achieving this result are the high pulse energy of the Performance, the patented Sweet Spot ResonatorÂ®, and the use of pulse shaping which varies the time-profile of the laser pulse to achieve the desired result.
MedicAlert were no strangers to laser processing as they had previously purchased two laser engraving machines from Rofin-Baasel to personalize the ID data on their emblems.